Air conditioning systems for building structures, dwellings or individual rooms have historically utilized a standard vapor compression cooling system to cool an interior volume of a building structure containing walls and/or ceilings. A traditional home or building air conditioning system is shown schematically in FIG. 1. As shown there, the air conditioning system typically includes an exterior positioned machine compartment housing mounted on a base platform where the housing contains a single outlet, single input compressor, a condenser, and a thermal expansion device. These traditional systems also typically include a fan associated with condenser, the size of which depends on various factors. For whole dwelling/building systems, which the compressor and condenser must provide higher cooling capacity, the systems are sized to match thermal load and are typically larger. Refrigerant fluid conduits deliver refrigerant through the vapor compression system and deliver refrigerant fluid that has passed through the compressor, the condenser and the throttling device to a single evaporator that operates at a single evaporator pressure located within an air passageway within the building structure. The air passageway could be an air duct, air vents of a room air conditioning system or a portion of the building's interior heating, ventilation and air conditioning machine compartment located within the building structure. Typically, the evaporator is positioned within the building's heating ventilation and air conditioning machine compartment. The air passageway typically has an air circulation fan associated with it to distribute air through the building structure or into a portion of the building structure. The air circulation fan delivers air across the single evaporator where it is cooled and the cooled air distributed to the volume of interior air to be cooled. Air is returned to the evaporator. Typically, a building structure may have an exterior air inlet/path that allows exterior air to enter, typically passively enter, the building structure from outside the building structure either directly into the air passageway or into the building structure air where the exterior air is then circulated within the building structure.
While this system does cool the building structure interior it typically does not allow for regulation of both the temperature and humidity of the interior of a building structure. When this traditional air conditioner is used, humidity is removed based upon the temperature of the single evaporator. A person within the interior volume of the building structure might want more or less humidity removed from the air within the building structure than what is allowed by such single evaporator systems.